Release relief valve for air-brake systems



April 7, 1925. v 1,532,126

H. L. EDRIDGE RELEASE RELIEF VALVE FOR AIR BRAKEQsYsfE'Ms Filed March 14. 1924 Patented Apr. 7, 1925.

BATEN'I? wsess RELIEF MW-E ee sis-BRAK sxs -sms er l efiee e h s! 14, 9% en e- 6W e- To all'whom it may concern:

" Be it known that I, HARTWELL L, Eng nes, a citizen of the United States, risidiiigat' Minneapolis, in the county of Henne'pilrand State of: Minnesota, have invented certain new and useful Improvements in Release Relief Valves for Air-Brake Systems; and-I do herebyvdeclar'e the following to be a 1111,

. clear,'and exact description of, the invention,

such aswill'enable othei's'skilled in the art tq'which it app'ertains o make endj e he same. invention provides an extremely simple; and; highly efiicient release reliejfi rel-vs fo e we systems, nd; generally stated, the invention: consists.- Qt the novel n tr ien, c mb na ens end. a an e.- men tsv ofs parts hereinafter described anddfined? the claims Air brake v systems are universally provided with relief valves usually, applied directly to the auxiliary; reservoirs; and; always arranged; tobe autometioallyclosed so that th r w be 0. n r; fhe ser i being accidentallyle tt open tordischarge of theai-l. to the atmosphere;

With the old or standard relief valves, it necessem .Q Q- iZ i E re to b relieved from pressure, 011, the operator to ho d the val e open during th enti e fbleed mg? 0 ,Ys 'et q an attics, teq i t hgiseyerql min e h bleed ng? 9 the" auxi iary le i ss i. w s equip e' 1th lfleh d 9 3' s eeellard i 4 s} hsm qre, zeq i ed' ee sider lelg rormed' by 0.11 PQ' QF andrqf co rse; 1,1 1 ee ib wee-ism a 1m e ent pes Qrm imp e ne! ""Myf' nve i tiei i provid s an, antemetiqally clqsi quick-open n r'elief. re ive, which, by e, simple and q iels sp nt-t e may be deemed, which. ill remain open ultiiig the bleeding operation, and which: gill then e mei iee lyz lole- W th "a ra n 'ee tsequ pre quick-opening? amer-1W1 t sim ler oes i 1 i J lng' ech relleii Opesms menses nd t e. s eeten e he bleed ng bf the. rs' er e rrs" end: other 9011* n eds; ore eirfhif ke see wi w slffoi evii "wh n s1 ht p hear n tikesyst i lbgsgfi sip ag in ut into opem'tienr I In the" accompa'n ing drawings, which illustrate the'invention, like characters indi ca'te "like parts; tli-ronghont the sevem1 views.

Referringto the drawings? l 2 Fig. 1 is a vertical section showing a frag lnent of auxiliary reservoir ofan air brake system and one of my improved quick opening' 'valvesappliedgthereto; and Fig. Qis ahoriiohtal section on the line 2., 2'o f Fig.1. 1 The auxiliary reservoir, a portion of which only is shown, may be of'the 'nsual oi""a 1' 1'y suitable c'or'istruction, as indicated by; the numeral" 3. In the constrnction 'illus trated; the cylinder 'structirre ofth relief valve-15s castingbolnprising a cylindef t cast integral with a base 5 'andfwi'th laterally spaced'parallel p'late lik'e flanges 6, the; latter being between thefo'penliower end of the cylinderaiid' the saidfb a'se. The cylinder 4: is'c'l o sed atits upper end, butis provided with one or more lateral air-discharge aort's 7' located below its closed head 'Wbning within the cylinder l is a piston head 81 havtnbnlejrstein 9. The base 5 has an axial recess 10 internally threaded sothat it 'is'v scrwed onto the hub 1T er aplng l2, the reduced" lower end of which latter'is externally threaded and screwed and extends" throiighf the top *otfthe eh l e t l e er fi f ra sth inediateportionbf the 'pliig 12is given the external forln'of nut or"'bolt head The lower the tnb ilar piston stein 9'works axiallythro'ugh the upper portion of the base 5 and'the latter, surrounding the 'lower enfdof said ste n ands'paced therefrom, has smear air; passage13 that extends down to charge of; air When the air brake system is 'a valve' seait inwardly opening cheek valvel5 normally pressedagainst the yams-seat by acoiledfspring 1 6. will res n lyePP' J he ir e eg .3- r t l" ti fmify'e if li li rs f i end t ea r p r s 7 "epere' e e's eeen e r ai discharge ha i s" Show; h i lve '1 a s eel that prdj'ectsboth upwardly and downhowever, being a minor fean h bi erveWe em 9, s owe pf fie l s pr v ded iew 'Q m re air Passages.

The l e kre ve-e s spnn a iis compr sedre y .tv el of a recess 18 formed in the upper portion of the plug 12 and having a diameter greater than that of the air passage through the lower portion of said plug.

Suitable means is provided for manually moving the piston 8 and check valve 15 to effect the initial discharge of air from the reservoir. For this purpose, I have shown two valvereleasing levers 19, the inner ends of which fit closely between the plate-like flanges 6 and are pivotally connected thereto near their inner ends by pivot pins 20. The short inner ends of said levers 19 are notched or bifurcated so that they embrace the ends of a pin 21 projected diametrically through the tubular piston stem 9. The free outer ends of the levers 19 are shown as provided with eyes to which releasing connections, such as chains, cables, or the like, may be attached and extended therefrom to opposite sides of the car, so that the opening of the relief valve may be easily accomplished by a person on either side of the car and without getting under the car.

Normally, the valve 15, the piston 8 and other movable parts will be in the positions best shown in Fig. 1 and, of course, the relief valve will then be closed. The spring 16 normally holds the check valve 15 against the seat 14 and the piston 8 will be positioned with its upper surface slightly above the secondary relief ports '7. Slow leakage of air between the piston 8 and cylinder a will permit said piston to move above said r secondary relief ports, or if there should be no such leakage, a very slight compression of air would permit said piston to assume substantially the position shown in Fig.1. The check valve 15, of course, engages the seat 14, forming a leak-proof joint.

To set the relief valve into action, it is only necessary, by movement of one or other of the levers 19, to move the piston 8 slightly downward so as to open the secondary ports 7 and, simultaneously therewith, cause the piston stem 9 to press the check valve 15 from its seat 1%, thereby opening the primary relief port 13. This permits the air to escape from the auxiliary reservoir into the primary relief port 13 and from thence through the air passages 17 and tubular valve stem 9 int-o the upper or outer end of the cylinder 4:, where the caged air, acting on the relatively large area of the piston 8 will, with very considerable force, hold the piston 8 in position to open the port 7 and the check valve 15 away from its seat 1 1 and in position to keep the primary relief port 13 open; and this discharge action will continue as long as the pressure in the auxiliary reservoir is materially above atmospheric pressure. Otherwise stated, the area of the piston 8 in respect to the diameter of the primary relief port 13 and valve seat 14: is so large that very slight pressure above atmospheric pressure will serve to keep said piston and check valve in open positions, thereby insuring bleeding of the auxiliary reservoir and air brake connections substantially down to atmospheric pressure, and thereupon, the relatively small force exerted by the spring 16 will become suflicient and active to automatically close the check valve 15 and move the piston 8 back to its normal position shown in Fig. 1. It will, of course, be noted that the piston 8 also acts as a valve to open and close the secondary air relief ports.

The eiiicieney and desirability of this improved check valve is thought to have been made obvious from the foregoing description and statements made.

If, at any time, it should be necessary to bleed the air brake system only partially, or, otherwise stated, to stop the discharge of air through the relief valve before the auxiliary reservoir has been reduced anywhere nearly down to atmospheric pressure. this may be done simply by forcing inward one of the levers 19, thereby forcing the check valve 15 against its seat 14. vWhen said check valve is once forced against its seat and there held for a short interval to prevent slight leakage between the piston 8 and cylinder 4, then said check valve will remain closed under the action of the spring 16 and will stop further bleeding of the air brake system. This action is especially important at times when the reservoirs are bled while connected in a train and when one of the triple valves may stick, causing the brakes to release and air to be admitted to the auxiliary reservoir that is being bled.

What I claim is:

1. A relief valve comprising a valve casing having a valve seat and a primary relief port connected therewith. a cylinder having a lateral secondary relief port. a piston working in said cylinder, normally closing said secondary relief port, an air passage opening into said primarv relief port and leading to the outer end of the cylinder, the initial opening movement of said check valve serving to admit air to the outer end of said cylinder and the air thus admitted. serving to move said piston into a position to open said secondary relief port and hold said check valve in a position to keep said primary relief port open until the pressure of air in said valve casing has been reduced toward atmospheric pressure.

2. A relief valve comprising a valve casing having a valve seat and a primary relief port connected therewith, a cylinder having a lateral secondary relief port. a piston working in said cylinder, normally closing said secondary relief port, and having a tubular valve stem with an air. passage opening into said primary relief port, the initial opening movement of said check valve serving to admit'air to the outer end of said cylinder and the air thus admitted serving to move said piston into a position to open saidsecondary relief port and hold said check valve in a position to keep said primary relief port open until the pressure of air in said valve casing has been reduced toward atmospheric pressure.

3. The structure defined in claim 2 in further combination with a spring yieldingly holding said check valve normally in a portclosing position.

4. The structure defined in claim 2 in further combination with manually operated means for moving said piston to open said secondary relief port and cause said check valve to open said primary relief port.

5. The structure defined in claim 2 in further combination With a spring yieldingly holding said check valve normally in a port- 7 closing position, and in further combination with a spring normally holding said check valve in a position to close said primary relief port and said piston in a position to close said secondary relief port.

In testimony whereof I affix my signature.

HARTWELL L. EDRIDGE. 

